Above Grade, Rapidly Deployable Foundation System

ABSTRACT

Disclosed is a rapidly deployable, above grade, low-thermal conducting, grillage-type foundation system made of composite materials, and erectable at or above grade for supporting structures like equipment shelters and communication masts. These units include generator sheds, communication shelters, fuel tanks, radio masts, and the like. The foundation system has one or more layers of beams laid at right angles to each other, and is used to disperse heavy point loads of a superstructure to an acceptable ground bearing pressure. Web stiffeners were affixed to foundation beams and vertical support members were fixed to the upper surface of the foundation beams, to stiffen the foundation and structure at every footing. The foundation is adapted to be installed with little site preparation, is easily transportable with a medium lift helicopter. Essentially, the foundation was engineered to only use steel in its assembly for the metal feet, angles, plates and the like.

CONTINUITY DATA

The present invention claims the benefit of prior filed U.S. Provisional application Ser. No. 62/134,513 filed 17 Mar. 2015 (pending), the content of which prior application is incorporated fully herein by reference.

INCORPORATION-BY-REFERENCE

Fully incorporated herein by reference is Applicants' engineering and specifications design document entitled: Rapid Deployment Communications Site (RDCS) Engineering Design Package.

FIELD OF THE INVENTION

The present invention is in the field of static building structures, particularly equipment shelters transportable to and erectable on remote sites (see Class 52). Specifically, the present invention relates to such equipment shelters having a foundation forming a discrete stable base that differ substantially in size and shape from the superimposed structural bodies it supports (see subclass 292). More specifically, the present invention relates to the openwork structure of the foundation, which when erected on a supporting surface defines an area having through passages or openings some of which may be filled by material in which the structure may be embedded (subclass 633).

BACKGROUND OF THE INVENTION

Experience has shown that the typical installation of a remote communications site (e.g., in Alaska) is both expensive and schedule restrictive. That is, coordinating an accelerated Alaska remote installation project with commercial helicopter schedules is expensive and risky, especially heavy-lift helicopters. There has been a long felt need in the industry to reduce:

helicopter dependency;

manpower requirements at the remote site;

environmental impact at the installation site; and

overall fabrication and installation costs.

As an example, all remote Alaska communication systems must consider and accommodate temperature extremes, wind extremes, seismic effects, site-specific topology, and dead weight. It would be a benefit to the industry to have a rapidly deployable foundation system upon which to construct an installation, such as remote communications site, that addresses all of these needs.

SUMMARY OF THE INVENTION

The present invention is an above grade, low-thermal conducting, grillage-type foundation system. More specifically, the present invention is a rapidly deplorable, grillage-type foundation system for installation at or above grade for supporting superstructure units, i.e., equipment shelters and communication masts. These units include generator sheds, communication shelters, fuel tanks, radio masts, and the like. Generally, grillage foundations are used to disperse heavy point loads of a superstructure to an acceptable ground bearing pressure. Grillage foundations comprise one or more layers of beams, usually laid at angles to each other.

The present foundation system is intended for transportation to and installation at rustic, remote and/or relatively unprepared field installation/staging sites. More specifically, the present invention is a composite (i.e., primarily made from “pultruded” fiberglass), and rapidly deployable foundation system. See patent no. U.S. Pat. No. 4,522,009 to Fingerson. Fabrication of the main frame beams and 95% of all structural components was derived from a type of material previously utilized in the manufacture of Arctic Glass Rig Mats (see patent no. U.S. Pat. No. 6,746,176 to Smith). Carbon steel was used for the metal feet, clips, angles and plates that are used to assemble the structure of the foundation.

The present system is adapted to be installed with little site preparation, and is easily transportable with a medium lift helicopter. For example, the foundation system can be transported onto a remote site/staging area in three standard 3500 lb. configured lifts or in two 7,500 lb. configured lifts, and erectable on site. The present foundation system can be partially pre-assembled in off-site, shipped to location, set with a squirt crane and erected in a matter of hours.

The present rapidly deployable foundation embodies desirable features and advantages long missing in the field. For example, its installation is less environmentally intrusive, especially in the extreme climactic environments of Alaska, in view of certain features of its material composition and structural design. The present foundation is substantially less weight than a comparable steel foundation supporting a similar superstructure, and has dielectric properties that resist the corrosion to which steel is subject. Of significant importance is the relative thermal neutrality of the present foundation and its reduced thermal transfer in view of permafrost bulb/environmental ecology considerations, e.g., to prevent heat transfer to the site grade surface.

Also of importance is that, when the present foundation is installed above grade, it still provides the support expected of more intrusive installations (e.g., concrete pilings), while providing superior stability for the supported buildings and structures. Specifically, the present foundation's design and installation are adapted to absorb perturbations of surface soils at its feet, while resisting movement at its centroid. This stability feature is especially important, for example, in remote installations requiring microwave RF communications, whose radio towers must maintain precise alignment to achieve communication links over long distances.

In a preferred embodiment, the present foundation system comprises parallel and cross-parallel structural beams constructed from material having a low dielectric and a low thermal conductivity. The main structural beams are co-joined at a centroid section of the foundation system. The centroid section is defined by the intersection of the parallel and cross-parallel foundation beams. Typically, for remote applications, a mounting means for a communication tower or mast is fixed to an upper surface of the parallel and cross-parallel foundation beams in the centroid section. The foundation's footings are adapted to affixed to a bottom surface of the parallel and cross-parallel foundation beams, and the footings are disposed to engage a grade surface matrix composed of the site materials. Web stiffeners are affixed to the parallel and cross-parallel foundation beams at every footing, and vertical support members fixed to the upper surface of the foundation beams, the vertical support members are positioned to support superstructure units. Generally, the vertical support members are associated with a footing.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an embodiment of the present rapidly deployable structure foundation.

FIGS. 2-a to 2-c are schematic illustrations of: (2-a) a top plan view, (2-b) an elevation view and (2-c) a bottom view of a long foundation beam of the present invention.

FIG. 3A is an elevation view of a crosstie beam of the present invention.

FIGS. 3B-a to 3B-c are schematic illustrations of: (B-a) bottom, (B-b) open-side perspective, and (B-c) open-side elevation views of a corner bracket for bracing a crosstie beam or an out-rigger beam to a backbone beam of the present invention.

FIGS. 4A-a & 4A-b are views illustrating: (A-a) top plan and (A-b) side elevation of a channel brace for fixing the angular relationship between intersecting foundation beams.

FIGS. 4B-a to 4B-d illustrate: (B-b) a top plan and (B-d) side elevation views of a brace plate, and (B-a) & (B-c) side plan views of two reinforcing plates.

FIGS. 5-a to 5-e are schematic illustrations of (5-a & 5-b) elevation views, and (5-c & 5-d) top & bottom plan views, and (5-e) a cross-sectional view of a web stiffener as used on the foundation beams of the present invention.

FIGS. 6-a to 6-e are schematic illustrations of (6-a & 6-b) top plan views, (6-c & 6-d) elevation views, and (6-e) a bottom view of features of a foundation foot as used on the foundation beams of the present invention.

FIGS. 7A-a to 7A-c are schematic illustrations of (7A-a) a perspective view, and (7A-b & 7A-c) side & front elevation views of a vertical support assembly as used on the foundation beams of the present invention, and showing its relationship to a cabin/equipment shack mounting beam.

FIGS. 7B-a to 7B-f are schematic illustrations of various views of a vertical support assembly of FIGS. 7A-a to 7A-c, detaining its component parts.

FIGS. 8A-a to 8A-c are various views illustrating: a tower mounting plate and its component parts.

FIG. 8B is a side elevation illustrating a tower mounting plate in place on a foundation beam and connected to a leg of a tower.

FIGS. 9-a & 9-b are schematic views of a grating installed between parallel foundation beams, the grating provides ballast areas around the present foundation system to provide stability for the supported structures.

REFERENCE NUMERALS

-   10—Rapid deployment structure foundation -   12—Foundation parallel beam, backbone (WF I-beam) -   13—Foundation cross-parallel beam -   14—Foundation beam, out-rigger -   16—Foundation beam, crosstie -   20—Channel beam brace -   22—Channel beam brace plate; 22.1 channel beam brace reinforcing     plate -   24—W-beam bean corner brace -   26—W-beam web stiffener; 26.1 stiffener internal brace; 26.2     stiffener upper brace (optional) -   30—Foundation foot assembly -   32—Foot beam -   34—Foot mounting plate -   36—Foot grade plate -   40—Vertical support assembly -   42—Cabin mounting beam -   44—vertical support beam -   46—Support top plate -   48—Support angle clips -   50—Tower mount assembly -   52—Tower mounting plate -   54—Tower plate nut -   56—Tower nut brace -   60—Ballast grating

DESCRIPTION OF THE INVENTION

Referring now to the drawings, the details of preferred embodiments of the present invention are graphically and schematically illustrated. Like elements in the drawings are represented by like numbers, and any similar elements are represented by like numbers with a different lower case letter suffix.

In the embodiment illustrated in the figures, the footprint of the embodiment is 36 ft×32 ft. FIG. 1 illustrates the major structural components comprising this exemplary embodiment of the present foundation system 10. For the purpose of clarity, hardware fasteners are not shown in the figures, but are known in the field and are selectable for practice in the present invention by one of ordinary skill in the art in view of the teachings and drawings contained herein. The example illustrated is adapted to support a tower (centrally located on the foundation) and an adjacent cabin or equipment shed. Other superstructure elements may be mounted on this embodiment as well, such as a fuel storage tank. Not shown is the grating used for containing the bottoming ballast for the foundation. However, see FIG. 9 and the exemplary Engineering & Design Specifications section regarding gratings and bottom ballast.

As shown in the example of FIG. 1, two parallel 12 in W-beams form the backbone beams 12 of the foundation 10. In this example, the backbone beams 12 are each a single 36 ft long W-beam. See FIGS. 2-a to 2-c for details of a backbone beam 12. Also shown are two parallel 12 in W-beams, each 32 ft long, forming the cross-rib beams 13 which intersect the backbone beams 12 at right angles. In this example, each cross-rib beam 13 is formed of two 12 ft long out-rigger beams 14 and an 8 ft long crosstie beam 16. The out-rigger beams 14 and the crosstie beam 16 are joined to the backbone beams 12 as illustrated in the figures. FIGS. 3A & 3B-a to 3B-c illustrate the details of: (3A) a crosstie beam 16, and (3B) the corner bracket 24 hardware adapted to join the crosstie beams 16 to the backbone beams 12. An out-rigger beam 14 is joined to a backbone beam 12 in a similar manner as a crosstie beam 16 by using similar corner bracket 24 hardware.

In the illustrated embodiment, the present foundation system 10 includes channel braces 20, which brace each of the out-rigger beams 14 relative to a backbone beam 12. FIGS. 4A-a & 4A-b show the details of a channel brace 20, and FIGS. 4B-a to 4B-d show details of the brace plate 22 & 22.1 hardware for joining a channel brace 20 to the W-beam of a out-rigger beam 14 or a backbone beam 12.

FIGS. 5-a to 5-e illustrate the use of web stiffeners 26 at positions on the foundation beams where a foundation foot 30 or a vertical support member 40 is mounted. The stiffener upper brackets 26.2 are used when the stiffener supports a vertical beam-member, such as a vertical support assembly 40. The foundation footings 30, see FIGS. 6-a to 6-e, were constructed of steel and adapted to embed into the surface matrix at grade to add stability to the foundation 10. The web stiffeners 26 were utilized at each of the vertical support members 40 to take a significant portion of the weight of the supported structure. FIGS. 7A-a to 7A-c illustrate an example of the structural relationship between a vertical support member 40 and mounting beam 42, and FIGS. 7B-a to 7B-f illustrate the details of a vertical support member 40 itself.

As noted above, a particularly useful application of the present foundation 10 is in the installation of a remote site having a tower-mounted communications system, e.g., microwave radio communications. In accomplishing this, the present foundation system 10 includes at its center-area, mounting plates 50 for such a tower. FIGS. 8A-a to 8A-c illustrate the details of a tower mounting plate 50, and FIG. 8B shows a tower mounting plate 50 disposed on the foundation system 10 and connected to the leg of a tower. Other means of accomplishing tower mounting plates disposed at the centroid of the foundation system 10 may be practiced in the present invention.

Bottoming ballast was utilized to provide the downward forces used with the present foundation system 10. In the example illustrated, bottoming ballast was accomplished using rock indigenous to the site of the installation. To contain the bottoming ballast, ballast grates 60 are disposed and secured in the W-beam channel between parallel sections foundation beams, as illustrated in FIGS. 9-a & 9-b. Also see Specification Attachment section 8.0 Rock Ballast Frame Design. The ballast grates 60 are made of pultruded fiberglass bar.

The attached exemplary Engineering & Design Specifications document (herein incorporated by reference) sets forth certain design considerations, calculations and engineering specs to practice the present above grade, rapidly deployable foundation system 10, and is referenced and included as part of the instant specification.

While the above description contains many specifics, these should not be construed as limitations on the scope of the invention, but rather as exemplifications of one or another embodiment thereof. Other variations are possible, which would be obvious to one skilled in the art. Accordingly, the scope of the invention should be determined by the scope of the appended claim(s) and equivalents, and not just by the embodiments. 

What is claimed is:
 1. An above grade, low-thermal conducting, grillage-type foundation system for supporting superstructure units, the foundation system comprising: a main frame (page 3, line 15), having at least two parallel (12) and two cross-parallel (13) beams constructed of a low thermal conductivity material, the parallel (12) and cross-parallel (13) beams of the main frame co joined at a centroid section of the foundation system; a centroid section defined by the intersection of the parallel (12) and cross-parallel (13) foundation beams; tower mounting means fixed to an upper surface of the parallel (12) and cross-parallel (13) foundation beams in the centroid section; foundation footings affixed to a bottom surface of the parallel (12) and cross-parallel (13) foundation beams, and the footings disposed to engage a grade surface matrix; web stiffeners disposed and affixed to the parallel (12) and cross-parallel (13) foundation beams at every footing; and vertical support members fixed to the upper surface of the foundation beams (12 & 13), the vertical support members adapted and positioned to support a superstructure unit, and the vertical support members associated with a footing.
 2. The above grade, low-thermal conducting, grillage-type foundation system of claim 1, wherein the parallel (12) and cross-parallel beams (13) are constructed of pultruded fiberglass (page 3, line 14).
 3. The above grade, low-thermal conducting, grillage-type foundation system of claim 2, wherein each parallel beam (12) is constructed as a single pultruded fiberglass beam.
 4. The above grade, low-thermal conducting, grillage-type foundation system of claim 2, wherein each cross-parallel beam (13) is constructed as a series of pultruded fiberglass beams, the cross-parallel beam series comprising out-rigger beams (14) and crosstie beams (16).
 5. The above grade, low-thermal conducting, grillage-type foundation system of claim 1, wherein a 90 degree angle is formed at each intersection of a parallel beam (12) and an out-rigger beam (14), with at least one 90 degree angle at each intersection having a hypotenuse defined by a channel beam brace (20) to stabilize the intersection of a parallel beam (12) and an out-rigger beam (14), and the combination of the parallel beam (12), the out-rigger beam (14), and the channel beam brace (20) providing a mount means supporting a ballast grating (60) for containing ballast material.
 6. The above grade, low-thermal conducting, grillage-type foundation system of claim 1, wherein the foundation footings affixed to the bottom surface of the parallel (12) and cross-parallel (13) foundation beams are adapted to stably engage a grade surface matrix. 